Rod-mill



(N0 Modlel.)-

T. W. PITCH.

ROD MILL.

No. 444,049. Patented Jan; '6, 1891.

INVENFTOR. $44 n. M

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,UNITED'STATES PATENT Orrrcn.

THOMAS W. FITCH, OF EDGEWOODVILLE, PENNSYLVANIA.

ROD-MILL.

SPECIFICATION forming part of Letters Patent No. 444,049, dated January6, 1891.

Application filed August 21, 1890. Serial No. 362,668. (No model.)

To all whom it mag concern.-

Be it known that I, THOMAS W. FITCH, of Edgewoodville, in the county ofAllegheny and State of Pennsylvania, have invented a new and usefulImprovement in Rod-Mills, of which the following is a full, clear, andexact description.

The object of my invention is to provide a rod-mill of improvedconstruction, especially adapted to rolling rods from blooms or billetsof'iron or copper,'which metals on account of their greater ductilitythan steel require special apparatus to be employed in their reduction.

It consists in combining with billet-rolls a train or series ofroll-passes (herein designated the intermediate train) so related inposition to the billet-rolls that the metal shall not enter the firstpass of the intermediate train until its rear end has emerged from thebillet-rolls. Within the scope of this feature of my invention theintermediate train and the final train or rod-train may be arranged in avarietyof ways relativelyto each other. For example, both maybe combinedin a single line or series, and other arrangements Wlll suggestthemselves to those familiar with the art. I shall describe, however, anarrangement which I deem to be preferable, and which I intend to claimspecifically. In so doing I shall refer to the accompanying drawing,which shows my improved mill in diagram plan view.

I do not show in detail the construction of the housings of the rolls,since these are so familiar to those skilled in the art that minutedescription and illustration of them would not serve to make thespecification more 1ntelligible.

In the drawing, 2 represents one of the usual heating-furnaces in whichthe metal bloom is heated as a preliminary step to its reduction. Therolls consist of three sets-a billet-train A, a rod-train B, and anintermediate train 0. The billet-train may consist of two sets of rolls3 and 4, of which the rolls 3 may be a three-high set, through which thebloom is passed back and forth, as shown by the dotted line, whichrepresents the course of the metal through the mill. From the rolls 3the rod travels in a loop to and through the rolls 4, and thence in adirect pass I) to the first pass 5 of the five roll-passes 5, 6,7, 8,and 9, constituting the intermediate train through which it travels inloops back and forth. From the rolls 9 the rod passes to the first passof the rod-train, and then travelsinloops through the six roll-passes1.0, 11, 12, 13, 14, and 15 of this train. From the last pass of therod-train the rod passes to the reel 16 or other apparatus by which itmay be coiled or bundled. Instead of arranging these rolltrains B and Cin the precise manner indicated, their relative position may be variedin the manner shown in my patent, No. 435,812, dated September 2, 1890.

The mill is provided with suitable guidetroughs 17 and curved guides orrepeaters 18, by which the rod is delivered from one rollpass to thenext, and the roll-passes are pref erably shaped in the usual manner, soas to reduce the rod alternately from a square or round section to anoval section, the repeaters being used to guide the squares or rounds inthe looped passes, and the guide-troughs to guide the ovals in thedirect passes, while in the looped passes the ovals are reflexed andinserted by manual work. The motive power for driving the rolls may bederived from a single engine .19, geared with the rolls by lines ofshafting 20, belts 21, and pinions 22 in such manner as to drive thetrains A, C, and B at successively greater rates of speed.

More than one driving-engine may, however,

be employed.

In order to adapt the mill to the successful reduction of rods of copperor iron to small diameter and to enable a large output to be produced, Iset the first pass 5 of the intermediate train 0 at such distance fromthe last pass 4 of the billet-mill that the front end of the rod shallnot reach the rolls 5 before its rear end has completely emerged fromthe pass 4. The front end of the rod is therefore inserted with tongs ofa Workman or by suitable feed-rollers, &c., into the pass 5. Thisarrangement enables me to drive the rolls of the train 0 at a very highrate of speed relatively to the rate of rotation of the billet trainrolls. For example, I may drive the rolls of the billet-train at a rateof ninety revolutions per minute, the rolls of the train 0 at twohundred and forty revolutions per minute, and the rolls of the rod-trainat five hundred revolutions per minute. Such ratio of revolution betweenthe rolls of the billet-train and the intermediate train would beimpossible it the rod were passed directly from the billet-train to theintermediate train and were in the passes of both trains at the sametime, since the increase of surface speed of the rolls would be far inexcess of the ratio of elongation of the rod by the rolls 4; but byplacing the rolls 4 and 5 so that there shall be the interruption in thepassage of the rod before noted, the increased speed becomes entirelypracticable and results in a capacity of the mill for a large output andfor a much greater reduction of the diameter of the rod than has beenpossible hitherto without reheating.

The advantages of my invention will be appreciated by those skilled inthe art, and need not be enumerated further than as already done in theforegoing description.

I claim-- 1. An improvement in the art of rolling metal rods, whichconsists in passing a heated billet through billet-rolls, reducing andelongating it thereby into rod form, and after passing it entirelythrough the billet-rolls introducing it into a more highly-speededrodtrain,wherebyindependent action of the rodtrain on the rod is securedand undue tension on the rod prevented, substantially as and for thepurposes described.

2. A rod-mill plant having billet-rolls, a series of roll-passes 5, 0,7, S,and 0, to which the rod travels in a direct pass from thebilletrolls and through which it travels in loops, and a final series ofroll-passes 1O, 11, 12, 13, ii, and 15, to which the rod travels in adirect pass and through which it travels in loops, substantially as andfor the purposes 40 described.

In testimony whereof I have hereunto set my hand this 16th day ofAugust, A. D. 1890.

THOMAS W. FITCH. Witnesses:

II. M. CoRWIN, W. II. JACKSON.

